Pistol barrel mounting structure



sept 21, 1965 F. A. PACHMAYR ETAL 3,207,037

PISTOL BARREL MOUNTING STRUCTURE 3 Sheets-Sheet 1 Filed Jan. 20, 1964 fn! .A

Sept. 21,A 1965 F. A. PACHMAYR ETAL 3,27037 PISTOL BARREL MOUNTING STRUCTURE Filed Ja'n. 20, 1964 5 Sheets-Sheet 2 wm@ NAN m WM5 .o Nuo [MH T A NGV..

SCPL 21 1955 F. A. PACHMAYR ETAL 3,207,037

PISTOL BARREL MOUNTING STRUCTURE 3 Sheets-Sheet 3 Filed Jan. 20, 1964 United States Patent O 3,207,037 PISTOL BARREL MOUNTING STRUCTURE Frank A. Tachmayr, Culver City, and George Hoenig, La Mirada, Calif., assignors to Pachmayr Gun Works, Inc., Los Angeles, Calif., a corporation of California Filed Jan. 20, 1964, Ser. No. 338,929 26 Claims. (Cl. 89-196) This invention relates to pistols having the type of construction utilized in the well known Colt automatic .45 caliber pistol, and is concerned primarily with means for improving the accuracy of such a gun.

An automatic pistol of the above mentioned type has a barrel which, at the time of firing, is held and located by a slide element, to which the sights of the gun are attached. After firing, this slide automatically recoils relative to the barrel, and relative to the body of the gun, to allow ejection of the cartridge case of the red round, and to allow feeding of the next successive round into the breech end of the barrel. As the slide moves rearwardly, the barrel swings slightly downwardly to avoid interference with rearward motion of the slide, and upon subsequent forward returning movement of the slide, the barrel is actuated slightly upwardly to its locking and firing position.

In automatic guns of this type as conventionally manufactured, the relationship of the various parts is such that, in the firing position of the parts, the barrel may be free for slight shifting movement relative to the slide, and is not therefore located precisely enough relative to the slide to assure accuracy of firing. This is partly true because of looseness which may occur at the forward end of the barrel and slide, between the barrel and a locating bushing disposed thereabout, and between this bushing and the slide. Further looseness may occur between the breech or rear end of the barrel and a link by which the barrel -is mounted for its slight downward swinging movernent, as well as between that link and the body of the gun to which it is pivotally connected.

The general object of the present invention is to provide means for increasing the accuracy of a gun of the .45 caliber automatic pistol type by increasing the preciseness with which the barrel of the gun is located and confined relative to the recoilable slide in the tiring condition of the gun. This result is attained in part by employment of a unique forward bushing structure which acts, in the firing condition, to embrace both the upperside and underside of the forward end of the barrel in a manner positively confining the barrel against looseness. More particularly, the barrel is mounted to pivot very slightly about essentially a predetermined axis relative to the bushing, upon recoiling movement of the gun, and the bushing has surfaces which at the time of firing engage the underside of the barrel at a location forwardly of that axis, and engage the upper side of the barrel at a location rearwardly of the axis. When the barrel swings slightly downwardly relative to the bushing, the barrel may move slightly out of engagement with these surfaces, and preferably into engagement with a second pair of surfaces which engage the upper side of the barrel forwardly of the specified axis, and engage the underside of the barrel rearwardly of that axis. These barrel engaging surfaces of the bushing may be formed in simple manner by precision boring through the bushing along two slightly different intersecting axes, disposed at a very slight angle to one another, with the bushing being held during boring by a suitable precision indexing xture.

Additional accuracy may be attained by means of a novel camming and self locking engagement of the bushing with the usual plunger which locks the bushing against removal from the slide. More particularly, the bushing ICC and plunger have a camming engagement at an effective camming angle which is very slight, and specifically is less than 20 degrees with respect to the front to rear direction of recoil of the slide, with this camming engagement acting to tightly hold the bushing upwardly against an under surface of the slide, and to do so in a manner such that this engagement is not broken by recoiling forces at the time of ring.

At the breech end of the barrel, increased accuracy of location of the barrel is attained by an improved pivoting link structure, in which the link which connects the barrel to the body of the gun has an upwardly facing surface which engages upwardly against a structure rigidly carried by the barrel in the tiring position of the parts, to thus rigidly and accurately locate the barrel relative to the link. Preferably, there are two such engaging shoulders or surfaces at opposite sides of the link, and a third at the upper end of the link.

With respect to the connection of the link itself to the body of the gun, greater accuracy is attained here by provision of a connecting pin which extends through the body and through the link, and which is formed separately from the slide locking arm with which it is integral in conventional guns of this type. Such separate formation of this pin enables the selection of different sizes of pins for different guns, so that each pin may t very precisely the particular gun in which it is to be held. The pin has `an outer head for engaging and holding the slide locking arm at one side of the gun body, and has a retaining ring or other retaining structure at the other side of the body, to engage the second end of the pin for holding the pin against removal from the gun.

Additional features of the invention have to do with a preferred manner in which the barrel mounting link is confined within a locating recess formed in the body or frame of the gun, and similarly the manner in which a lug structure on the barrel, which is connected to the link, is confined between two surfaces in the body.

The above and other features and objects of the invention will be better understood from the following detailed description of the typical embodiment illustrated in the accompanying drawings, in which:

FIG. l is a side view, partially broken away, of a pistol constructed in accordance with the invention;

FIG. 2 is a fragmentary view similar to FIG. l, but showing the pistol in recoiled position;

FIG. 3 is an enlarged front view taken on line 3-3 of FIG. l;

FIGS. 4 and 5 are enlarged transverse sections taken on lines 4-4 and 5 5 respectively of FIG. 1;

FIG. 6 is a greatly enlarged representation of the barrel and its mounting parts;

FIG. 7 is a still further enlarged representation of the barrel mounting surfaces of the bushing;

FIG. 8 is a perspective view of the link which mounts the breech end of the barrel and related parts;

FIG. 9 is an exploded perspective of the link mounting pin and associated slide stop arm;

FIG. l0 is taken on line 10-10 of FIG. 1; and

FIG. 11 is taken on line 11-11 of FIG. 10.

With reference first to FIG. 1, we have shown at 10 a .45 caliber automatic pistol Which is of conventional and well known construction except with respect to the particular features illustrated in detail, and discussed hereinbelow. This gun includes the usual main body 11 having a handle portion 12 within which a magazine containing several rounds of ammunition is contained, with the gun being red by actuation of a conventional trigger 13. The tiring barrel of the gun is shown at 14, and is contained within a slide 15 which is mounted to the body for front to rear recoiling movement between the positions of FIGS. 1 and 2. As seen best in FIG. 5, the slide is mounted and guided for such recoiling movement, parallel to the firing axis 16 of barrel 14, by reception of two guiding ribs 17 of the slide within guide ways 18 in the receiver portion 19 of the gun body 11, and by corresponding reception of two guiding lugs 20 formed at the upper edge of the receiver within mating guide ways 21 formed in the inner surfaces of the two side walls 22 of the slide. In the fully recoiled position of FIG. 2, the empty case of an expended round is ejected from the gun through opening 23 at the top and one side of the slide, and a next successive round is fed into the breech end 24 of the barrel from the magazine contained within handle 12. Also, rearward movement of the slide automatically cocks the hammer 25 to the FIG. 2 position, for the next firing operation.

The forward end of barrel 14 is located relative to slide 15 by means of a tubular bushing 26 which is disposed about the forward end of the barrel in engagement with its external cylindrical surface 27. To receive bushing 26, slide 15 contains a cylindrical passage 28 which is centered about an axis 16, which passage is circularly continuous except at the location of an interruption 29 (FIG. 3) through which passage 27 communicates with a second but smaller internally cylindrical passage 129 containing a plunger 30. Passage 129 is centered about an axis 31 which is offset downwardly beneath and parallel to main axis 16 of the gun.

The outer cylindrical surface 32 of bushing 26 is a relatively close fit within cylindrical passage 28 of the slide, and at its forward end the bushing is provided with a ange 33 engageable with the forward end of the slide t0 limit rearward movement of the bushing relative to the slide. At a location just rearwardly of ange 33, the bushing carries the usual bayonet lug 34 (FIG. 3), which is receivable within the usual arcuate bayonet groove 35 formed in the side wall of the slide, to secure the bushing to the slide. As will be apparent, the bushing is attached to the slide by first passing lug 34 rearwardly through the interruption 29 of FIG. 3, with the bushing in the broken line position 26 of FIG. 3, and then swinging the bushing to the full line position of that figure.

The bushing is retained in its full line position by means of the plunger 30, which is externally cylindrical and a close fit within passage 29, and is spring pressed forwardly by a coil spring 36. The rear end of spring 36 engages a conventional part 37 which exerts rearward force against the receiver portion of the gun body, so that the spring yieldingly resists rearward recoiling movement of the slide. The forward end of plunger 30 is received within an arcuate notch 37 formed in the lower downwardly enlarged portion 38 of bushing flange 33, to lock the bushing against swinging movement to its broken line position of FIG. 3.

An important feature of the present invention resides in the unique type of camming engagement which we provide between bushing 26 and plunger 30. Particularly, it is noted in FIG. 1 that plunger 30 has at its forward end an annular gradually tapering external surface, of frusto-conical configuration centered about axis 31. This surface 39 engages a correspondingly tapering arcuate under surface 40 forming notch 37 in the bushing. This camming configuration of surfaces 39 and 40 causes plunger 30 to automatically cam bushing 26 upwardly into tight engagement with the upper portion of cylindrical surface 27 of the slide, and to at all times hold the bushing in that position in a manner taking up -any looseness which may be present between the bushing and the slide, and thereby increasing the accuracy of the gun. In order to prevent cam surfaces 39 and 40 from vibrating out of engagement at the time of firing, and thereby releasing the accurate locating forces exerted by the plunger against the bushing, it is also highly important that the taper of surfaces 39 and 40 be Very gradual. When the tapers are made gradual in this manner, the frictional engagement between surfaces 39 and 40 prevents such relative dislocation of the parts. More specifically, it is preferred that surfaces 39 and 40 have an effective camming angle less than 20 degrees with respect to axis 31, and preferably less than 1() degrees, the optimum arrangement presently being considered to be a 7 degree cam angle.

The breech end of barrel 14 is mounted to the gun body by means of a mounting link 41 which is pivotally connected by a pin 42 to a depending lug 43 which is integral with barrel 14. Link 41 is also pivotally connected by a second pin 44 to the receiver portion of the gun body, so that the link allows slight rearward and downward swinging movement of the breech portion'of barrel 14, between the positions of FIGS. 1 and 2, as slide 15 recoils re-arwardly. Such slight swinging movement of the barrel is conventional, but the construction and mounting of the link and its related parts have been irnproved in the present invention to increase the accuracy and rigidity with which the breech end of the barrel is held in precisely predetermined position in the FIG. 1 firing condition of the gun.

To attain this result, link 41 is given the configuration which is brought out in FIGS. 5 and 6, including a lower relatively wide portion 44 having parallel opposite side surfaces 45, with an upper reduced width portion 46 projecting upwardly from portion 44. This portion 46 projects upwardly into a recess 47 formed by and between two downwardly projecting parallel arms 48 of the bifurcated lug 43 on the barrel. Arms 48 have at their lower ends horizontal aligned surfaces 49, offset rearwardly of the axis of pins 42 and 44, and positioned for engagement by upwardly facing horizontal surfaces or shoulders 50 formed on link 41 when the link and barrel are in their FIG. 6 firing positions. The upwardly projecting portion 46 of link 41 is connected to arms 48 by means of the pin 42, which is a close fit within registering apertures in the two connected parts. Rearwardly of pin 42, the upper portion 46 of link 41 may have an upwardly facing surface 51 (FIG. 6), which is engageable upwardly against an under surface 52 formed in lug 43 between its two arms 48. As will be apparent, the axes of pins 42 and 44 are disposed transversely of a plane containing the two previously discussed axes 16 and 31, and the engaging surfaces of arms 48 and portion 46 of link 43 are disposed perpendicular to the axes of pins 42 and 44. Portion 46 is dimensioned very precisely to accurately fit within the recess 47 between arms 48, and to simultaneously engage both sides of that recess in a manner preventing any lat- .eral shifting movement of the link relative to the barrel.

As seen best in FIG. 5, pin 44 extends through lower portion 144 of link 41, and also through the two side walls 53 of receiver portion 19 yof the gun body. The pin is externally cylindrical and accurately dimensioned to fit very closely within the mating passages formed in the parts connected thereby, so that no looseness can develop at this point. At the outer side of the body, this pin is connected to the usual receiver stop arm 54 (FIGS. 1 and 9), which is actuable in conventional manner to engage a notch 55 (FIG. 2) in slide 15 after firing of the last round in the gun, to hold the slide in open position. To enable more accurate fitting of the pin 44 to link 41 and the receiver, and to enable selection as between a large number of different pins until an accurately fitting pin is found, we form pin 44 separately from arm 54, rather than integrally therewith as in conventional guns. More particularly, pin 44 extends through an opening 56 formed in arm 54, and has an enlarged head 57 at the outer side of the arm holding the arm against the side of the gun body. At the opposite side of the gun body, pin 44 has an annular recess or groove 58, typically of the tapering configuration illustrated in FIG. 5, and which removably receives a resilient locking C ring or snap ring 59 for releasably holding pin 44 and the other parts in assembled relation.

To prevent lateral movement of link 41 within the gun receiver, we accurately mill in the bottom wall of the receiver a recess having two parallel opposite side walls 60 (FIG. 5) which are planar and disposed parallel to axes 16 and 31, and which are accurately spaced to exactly receive lower portion 144 of link 41, and simultaneously engage both of the opposite side surfaces 45 of that link to positively prevent lateral movement of the link relative to the gun body. To attain a similar lateral locating action with respect to bifurcated lug 43 carried by barrel 14, we braze or otherwise permanently secure to the parallel opposite side surfaces 61 of lug 43 carried by the barrel one or more thin shims 62, which are selected to enlarge lug 43 to a condition in which it fits precisely within and between the two parallel side wall surfaces 63 formed by the gun receiver or body at opposite sides of lug 43. Thus, the lug 43 as enlarged by the shims, simultaneously engages both of the wall surfaces 63, in planes disposed parallel to axes 61 and 31, and perpendicular to pins 42 and 44, to further assist in retaining lug 43 and the barrel against lateral shifting movement.

When the breech end of the barrel swings downwardly and rearwardly to the FIG. 4 position, the barrel pivots relative to bushing 26 about an axis represented at 64 in FIG. 6. This pivotal movement is very slight, being less than 2 degrees, and in most cases less than l degree, and preferably being approximately zero degrees land thirty nine minutes. By the time the slight swinging movement and unlocking of the barrel is completed, the bushing 26 has started to move rearwardly, ultimately to a location near the middle of the barrel, and specifically to the broken line position of FIG. 6. The angle of downward displacement of the breech end of the barrel is illustrated in broken lines at 65 in FIG. 6. To allow for this swinging movement of the barrel relative to the bushing, while at the same time assuring very rigid and precise holding of the barrel in its firing position, we form the bushing internally with a first pair of internal surfaces 66 and 67 for holding the barrel in firing condition, and a second pair of surfaces 68 and 69 for engaging the barrel in its downwardly swung position. Surface 66 meets and merges with surface 68 at the location of a plane 70 which is disposed transversely of axis 16 of the bushing and contains axis 64. Similarly, surfaces 67 and 69 also meet at plane 70. Surface 66 is semi-cylindrical, and centered about axis 16, and engages the upper half of the barrel, just rearwardly of plane 70, while surface 67 is semi-cylindrical and centered about axis 61 to engage the bottom half of barrel 14 just forwardly of plane 70. As will be apparent, the diameter of surfaces 66 and 67 corresponds precisely to the external diameter of surface 28 of the barrel, to thereby engage the barrel entirely about its periphery and in precise locating relationship in the firing position of the gun. Surfaces 68 and 69 are similarly semi-cylindrical sur-faces, of the same diameter as are surfaces 66 and 67 but disposed about an axis 71 which intersects axis 16 at 64 and at an angle corresponding to the angle 65 of FIG. 6, so that in the slightly downwardly swung position of the barrel, it is engaged and accurately located by surfaces 68 and 69.

At the upper portion of the -breech end of barrel 14, there is provided an arcuate rearwardly projecting lug 74 (FIGS. 6 and 10), which is received between two vertical parallel planar Side wall `surfaces 75 of a recess formed in slide 15. This lug 74 forms in effect a rearward partial cylindrical continuation of the barrel, and in conventional .45 caliber guns is loose enough within the space provided between wall surfaces 75 to leave small clearance spaces at opposite sides of lug 74. In the present invention, however, the lug 74 is purposely made wide enough to occupy the entire space between side wall surfaces 75, and is ground to provide two vertical parallel opposite side surfaces 76 which simultaneously engage and are accurately located by and between surfaces 75. This confinement of lug 74 coacts with the rigid mounting of the lower portion of the breech by link 41, to further assist in accurately locating the barrel.

A preferred method of altering a conventional .45

6 caliber gun to have the close t of FIG. l0 at lug 74 is to first compress lug 74 radially, as by placing the lug over an arcuate convex surface 78 of an anvil 81 (FIG. 11) and then striking the upper side of the lug a heavy blow or series of blows with the concave surface 80 of a hammer or forging tool 89 (as indicated diagrammatically by the arrow '76 in FIG. 11), and with a force acting to upset or laterally enlarge lug 74 to a condition in which it is slightly wider than the spacing between Iside wall surfaces 75 of the mated portion of the slide. Next, the side surfaces 76 of lug 74 are ground to remove just enough of the expanded material of lug 74, at opposite sides thereof, to provide the accurately spaced side surfaces 76 for engaging surfaces 75. Also, the forging operation lengthens the lug 74 axially, in a rearward direction, following which the rear face is ground off transversely in a slightly lengthened condition in which it fits tightly against the forward facing surface 174 of the slide.

To now describe a cycle of operation of the gun, assume that the magazine is lproperly loaded with live rounds, Aand that the gun is assembled and in the condition of FIG. 1. The gun may then be manually cocked for the first round, aimed lby use of sights 71 carried by slide 15, and then fired. At the instant of firing, the forward end of the barrel is held accurately in fixed position relative to the slide1 and therefore relative to sights 71, by engagement of bushing surfaces 66 and 6,7 with the barrel. Also, the bushing is itself held against any displacement from a predetermined position relative to the slide by virtue of the camming engagement of plunger 30 with the bushing at 39-40, as previously discussed. The breech end of the barrel is precisely located in accurately repeatable position by link 41, and especially by the upward engagement of shoulders 5t) and 51 of the link with the corresponding portions of barrel carried lug 43. The precisely ground cylindrical pins 42 and 44 prevent looseness at the pivot points of link 41, and the engagement of link 41 with body surfaces 60, and engagement of shims 62 with the body, as well as the tight engagement of lug 74 (FIG. l0) between surfaces 75 and against surface 174, all add to the effectiveness with which the breech end of the barrel is located. At the same time, the arcuate lugs 72 (FIGS. l and 6) on the barrel engage upwardly against the underside of the slide, to further locate the barrel.

We claim:

1. A gun including a body, a ybarrel movably mounted to said body, a bushing disposed about and positioning said barrel toward the muzzle end thereof, and means mounting said barrel for slight upward and downward swinging movement of the breech end thereof relative to said bushing and about essentially an axis extending transversely of said bushing at essentially the location thereof, said bushing having a first bushing surface positioned to engage and embrace the underside of said barrel at a location forwardly of said axis, and having a second vbushing surface positioned to engage and embrace the upper side of `said barrel at a location rearwardly of said axis, said surfaces being positioned for movement of said barrel into locating engagement with both of said surfaces by said slight upward swinging movement of the breech end of the barrel, and for movement of the barrel out of said locating engagement with both of said surfaces 4by said slight downward swinging movement of the breech end of the barrel, said first bushing surface extending rearwardly substantially to a transverse plane containing said axis and said second Ibushing surface extending forwardly substantially to the same transverse plane to confine the barrel between the extremities of said surfaces during said pivotal movement.

2. A gun including a body, a barrel movably mounted tol said body, a bushing disposed about and positioning said barrel toward the muzzle end thereof, and means mounting said barrel for slight upward and downward swinging movement of the breech end thereof relative to said Abushing and about essentially an axis extending transversely of said bushing at essentially the location thereof, said bushing having a first essentially arcuate bushing surface positioned to essentially arcuately engage and embrace the underside of said barrel at a location forwardly of said axis, and having a second essentially arcuate bushing surface positioned to essentially arcuately engage and embrace the upper side of said barrel at a location rearwardly of said axis, said surfaces being positioned for movement of said vbarrel into locating engagement with both of said surfaces by said slight upward swinging movement of the breech end of the barrel, and for movement of the ybarrel out of said locating engagement with both of said surfaces by said slight downward swinging movement of the ybreech end of the barrel, said first bushing Surface extending rearwardly substantially to a transverse plane containing said axis and said second bushing surface extending forwardly substantially to the same transverse plane to confine the barrel between the extremities of said surfaces during said pivotal movement.

3. A gun including a body, a barrel movably mounted to said body, a bushing disposed about and positioning l said barrel toward the muzzle end thereof, and means mounting said barrel for slight upward and downward swinging movement of the breech end thereof relative to said bushing and about essentially an axis extending transversely of said bushing at essentially the location thereof, said bushing having a first essentially semi-cylindrical bushing surface positioned to essentially semicircularly engage and embrace the underside of said barrel at a location forwardly of said axis, and having a second essentially semi-cylindrical bushing surface positioned to engage and embrace the upper side of said barrel at a location rearwardly of said axis, said surfaces being positioned for movement of said barrel into locating engagement with both of said surfaces by said slight upward swinging movement of the breech end of the barrel, and for movement of the barrel out of said locating engagement with both of said surfaces by said slight downward swinging movement of the breech end of the barrel, said first bushing surface extending rearwardly substantially to a transverse plane containing said axis and said second bushing surface extending forwardly substantially to the same transverse plane to confine the barrel between the extremities of said surfaces during said pivotal movement, said semi-cylindrical surfaces being centered about a common axis which is essentially coincident with the longitudinal axis of said barrel when the barrel is in engagement with said surfaces.

4. A gun including a body, a barrel movably mounted to said body, a bushing disposed about and positioning said barrel toward the muzzle end thereof, and means mounting said barrel for slight upward and downward swinging movement of the breech end thereof through a small angle less than two degrees, relative to said bushing and about essentially an axis extending transversely of said bushing at essentially the location thereof, said bushing having a first bushing surface positioned to engage and embrace the underside of said barrel at a location forwardly of said axis, and having a second bushing surface positioned to engage and embrace the upper side of said barrel at a location rearwardly of said axis, said surfaces being positioned for movement of said barrel into and out of locating engagement therewith by said slight upward and downward swinging movement respectively of the breech end of the barrel, said bushing having two additional bushing surfaces positioned to essentially engage and locate the underside and upper side respectively of the barrel when it is swung downwardly through said angle less than two degrees, said additional surfaces being located rearwardly and forwardly respectively of said transverse axis.

5. A gun including a body, a barrel movably mounted to said body, a bushing disposed about and positioning said barrel toward the muzzle end thereof, and means mounting said barrel for slight upward and downward swinging movement of the breech end thereof through a small angle less than two degrees, relative to said bushing and about essentially an axis extending transversely of said bushing at essentially the location thereof, said bushing having a first bushing surface positioned to engage and embrace the underside of said barrel at a location forwardly of said axis, and having a second bushing surface positioned to engage and embrace the upper side of said barrel at a location rearwardly of said axis, said surfaces being positioned for movement of said barrel into and out of locating engagement therewith by said slight upward and downward swinging movement respectively of the breech end of the barrel, said bushing having two additional bushing surfaces positioned to essentially engage and locate the underside and upper side respectively of the barrel when it is swung downwardly, said additional surfaces being located rearwardly and forwardly respectively of said transverse axis, said first and second bushing surfaces being essentially arcuate and centered about a first longitudinal axis, said additional bushing surfaces being essentially arcuate and centered about a, second longitudinal axis intersecting said first longitudinal axis at a slight angle less than two degrees.

6. A gun including a body, a barrel movably mounted to said body, a bushing disposed about and positioning said barrel toward the muzzle end thereof, and means mounting said barrel for slight upward and downward swinging movement of the breech end thereof through a small angle less than two degrees, relative to said bushing and about essentially an axis extending transversely of said bushing at essentially the location thereof, said bushing having a first bushing surface positioned to engage and embrace the underside of said barrel at a location forwardly of said axis, and having a second bushing surface positioned to engage and embrace the upper side of said barrel at a location rearwardly of said axis, said surfaces being positioned for movement of said barrel into and out of locating engagement therewith by said slight upward and downward swinging movement respectively of the breech end of the barrel, said bushing having two additional bushing surfaces positioned to essentially engage and locate the underside and upper side respectively of the barrel when it is swung downwardly, said additional surfaces being located rearwardly and forwardly respectively of said transverse axis, said first and second bushing surfaces being essentially semi-cylindrical and complementary and centered about a first longitudinal axis, said additional bushing surfaces being essentially semi-cylindrical and complementary and centered about a second longitudinal axis intersecting said first longitudinal axis at a slight angle less than two degrees, said first and second surfaces meeting and merging with said additional surfaces at the location essentially of a common transverse plane containing said transverse axis.

7T A gun including a body, a barrel movably mounted to said body, a bushing disposed about and positioning said barrel toward the muzzle end thereof, a slide mounted to said body for front to rear sliding movement relative to said barrel and carrying said bushing for sliding movement therewith, and means mounting said barrel for slight upward and downward swinging movement of the breech end thereof through a small angle less than two degrees relative to said bushing and about essentially an axis extending transversely of said bushing at essentially the location thereof, said bushing having a first bushing surface positioned to engage and embrace the underside of said barrel at a location forwardly of said axis, and having a second bushing surface positioned to engage and embrace the upper side 0f said barrel at a location rearwardly of said axis, said surfaces being positioned for movement of said barrel into locating engagement with both of said surfaces by said slight upward swinging movement of the breech end of the barrel, and for movement of the barrel out of said locating engagement with both of said surfaces by said slight downward swinging movement of the breech end of the barrel, said first bushing surface extending rearwardly substantially to a transverse plane containing said axis and said second bushing surface extending forwardly substantially to the same transverse plane to confine the barrel between the extremities of said surfaces during said pivotal movement.

8. A gun including a body, a barrel having a longitudinal axis, -a slide mounted to said body for front to rear recoiling movement relative thereto in a front to rear direction, a bushing carried by said slide disposed about and centering said barrel, a recoil spring yieldingly urging said slide forwardly relative to said body, a plug carried by said slide for movement therewith and against which the forward thrust of said spring is exerted, said bushing having a portion containing a notch which receives a forward portion of said plug to form a lock therewith securing said plug against forward movement and locking the bushing to the slide, said notch and said forward portion of said plug having a camming engagement at an effective camming angle of less than 20 degrees with respect to said front to rear direction tending to cam 'said bushing transversely as a result of the forward force exerted by said spring to thereby take up transverse looseness of the bushing and assure tight retention thereof in fixed position relative to the slide.

9. A gun including a body, a barrel having a longitudinal axis, a slide mounted to said body for front to rear recoiling movement relative thereto in a front to rear direction, a bushing carried by said slide disposed about and centering said barrel, a recoil spring yieldingly urging said slide forwardly relative to said body, a plug carried by said slide for movement therewith and against which the forward thrust of said spring is exerted, said bushing having a portion containing a notch whichreceives a forward portion of said plug to form a lock therewith securing said plug against forward movement and locking the bushing to the slide, said plug having a forwardly tapering peripheral surface at the forward end thereof, said bushing having a correspondingly tapering arcuate surface defining said notch and engageable with said tapering surface of the plug in a relation tending to cam the bushing laterally as a result of the forward force exerted by said spring to thereby take up looseness of the bushing and assure tight retention thereof in fixed position relative to the slide, said tapering surfaces being disposed at an effective camming angle of less than about 20 degrees with respect to said front to rear direction.

10. A gun including a body, a barrel having a longitudinal axis, a slide mounted to said body for front to rear recoiling movement relative thereto in a front to rear direction, a bushing carried by said slide disposed about and centering said barrel, a bayonet connection mounting the bushing within a passage in the slide and releasable by rotary motion of the bushing, a recoil spring yieldingly urging said slide forwardly relative to said body, a plug carried by said slide for movement therewith and against which the forward thrust of said spring is exerted, said bushing having a portion containing a notch which receives a forward portion of said plug to form a lock therewith securing said plug against forward movement and locking the bushing against said releasing rotary motion relative to the slide, said plug having a forwardly tapering peripheral surface at the forward end thereof, said bushing having a correspondingly tapering arcuate surface defining said notch and engageable with said tapering surface of the plug in a relation tending to cam the bushing laterally as a result of the forward force exerted by said spring to thereby take up looseness of the bushing and assure tight retention thereof in fixed position relative to the slide, said tapering surfaces being disposed at an eective camming angle of less than about 20 degrees with respect to said front to rear direction, said plug being free for slight rearward movement relative to the slide and against the force of said spring to a position out of the path of said releasing rotary motion of the bushing to enable removal of the bushing from the slide.

11. A bushing to be mounted in a gun slide to slidably receive and locate a coacting gun barrel which is mounted for slight downward and upward swinging movement about a predetermined transverse axis relative to the bushing, said bushing having a first bushing surface positioned to engage and embrace the underside of said barrel at a location forwardly of said axis, and having a second bushing surface positioned to engage and embrace the upper side of said barrel at a location rearwardly of said axis, said surfaces being positioned for movement of said barrel into locating engagement with both of said surfaces by said slight upward swinging movement of the breech end of the barrel, and for movement of the barrel out of said locating engagement with both of said surfaces by said slight downward swinging movement of the breech end of the barrel, said first bushing surface extending rearwardly substantially to a transverse plane containing said axis and said second bushing surface extending forwardly substantially to the same transverse plane to confine the barrel between the extremities of said surfaces during said pivotal movement.

12. A bushing to be mounted in a gun slide to slidably receive and locate a coacting gun barrel which is mounted for slight downward and upward swinging movement about a predetermined transverse axis relative to the bushing, said bushing having a first essentially semi-cylindrical bushing surface positioned to engage and embrace the underside of said axis, and having a second essentially semi-cylindrical bushing surface positioned to engage and embrace the upper side of said barrel at a location rearwardly of said axis, said surfaces being positioned for movement of said barrel into locating enga-gement with both of said surfaces by said slight upward swinging movement of the breech end of the barrel, and for movement of the barrel out of said locating engagement with both of said surfaces by said slight downward swinging movement of the breech and of the barrel, said first bushing surface extending rearwardly substantially to a transverse plane containing said axis and said second bushing surface extending forwardly substantially to the same transverse plane to confine the barrel between the extremities of said surfaces vduring said pivotal movement.

13. A bushing to be mounted in a gun slide to slidably receive and locate a coacting gun barrel which is mounted for slight downward and upward swinging movement about a predetermined transverse axis relative to the bushing, said bushing having a first bushing surface positioned to engage and embrace the underside of said barrel at a location forwardly of said axis, and having a second bushing surface positioned to engage and embrace the upper side of said barrel at a location rearwardly of said axis, said surfaces being positioned for movement of said barrel into and out of locating engagement therewith by said slight upward and downward swinging movement respectively of the breech end of the barrel, said bushing having two additional bushing surfaces positioned to essentially engage and locate the underside and upper side respectively of the barrel when it is swung downwardly, said additional surfaces being located rearwardly and forwardly respectively of said transverse axis and meeting said first and second bushing surfaces respectively in substantially a common transverse plane containing said axis.

14. A bushing to be mounted in a gun slide to slidably receive and locate a coating gun barrel which is mounted for slight downward and upward swinging movement about a predetermined transverse axis relative to the bushing, said bushing having a first bushing surface positioned to engage and embrace the underside of said barrel at a location forwardly of said axis, and having a second bushing surface positioned to engage and embrace the upper side of said barrel at a location rearwardly of said axis, said surfaces being positioned for movement of said barrel into and out of locating engagement therewith by said slight upward and downward swinging movement respectively of the breech end of the barrel, said bushing having two additional bushing surfaces positioned to essentially engage and locate the underside and upper side respectively of the barrel when it is swung downwardly, said additional surfaces being located rearwardly and forwardly respectively of said transverse axis, said first and second bushing surfaces being essentially semicylindrical and complementary and centered about a first longitudinal axis, said additional bushing surfaces being essentially semi-cylindrical and complementary and centered about a second longitudinal axis intersecting said first longitudinal axis at a slight angle less than two degrees.

15. The combination comprising a bushing to be mounted in a gun slide to slidably receive and locate a coacting barrel, bayonet connection means for securing said bushing to the slide, and a plug to be spring pressed forwardly and receivable within a notch in the slide, said plug and notch have a camming engagement at an effective camming angle less than degrees tending to cam said bushing transversely as a result of the exertion of forward force by said plug.

16. A gun including a body, a barrel movably mounted to said body, a bushing disposed about and positioning said barrel toward the muzzle end thereof, a slide mounted to the body for front to rear recoiling movement relative thereto, a connecting structure projecting downwardly from the breech end of said barrel, a link, a first pin attaching said link to said body for relative pivotal movement about a first transverse axis, a second pin attaching said link to said connecting structure for relative pivotal movement about a second transverse axis above said first axis and in a relation mounting the breech end of said barrel for slight rearward and downward movement, said slide having a portion engageable with said barrel upon forward movement of the slide to shift said barrel slightly upwardly and forwardly to a predetermined firing position thereof, said link having an upper generally horizontal surface movable into engagement upwardly against a general horizontal undersurface of said connecting structure in abutting engagement therewith upon movement of said barrel to said firing position.

17. A gun including a body, a barrel movably mounted to said body, a bushing disposed about and positioning said barrel toward the muzzle end thereof, a slide mounted to the body for front to rear recoiling movement relative thereto, a connecting structure projecting downwardly from the breech end of said barrel, a link, a first pin attaching said link to said body for relative pivotal movement about a first transverse axis, a second pin attaching said link to said connecting structure for relative pivotal movement about a second transverse axis above said first axis and in a relation mounting the breech end of said barrel for slight rearward and downward movement, said slide having a portion engageable with said barrel upon forward movement of the slide to shift said barrel slightly upwardly and forwardly to a predetermined firing position thereof, said body containing an upwardly facing recess movably receiving and closely fitting a lower end portion of said link and having parallel opposite side walls, said lower end portion of the link having parallel opposite side surfaces spaced precisely in substantially exact correspondence with the spacing of said recess walls and simultaneously engaging both of said recess walls to precisely confine and locate the link and thereby the barrel against lateral shifting movement.

18. A gun including a body, a barrel movably mounted to said body, a bushing disposed about and positioning said barrel toward the muzzle end thereof, a slide mounted to the body for front to rear recoiling movement relative thereto, a connecting structure projecting downwardly from the breech end of said barrel, a link, a first pin attaching said link to said body for relative pivotal movement about a first transverse axis, a second pin attaching said link to said connecting structure for relative pivotal movement about a second transverse axis above said first axis and in a relation mounting the breech end of said barrel for slight rearward and downward movement, said slide having a portion engageable with said barrel upon forward movement of the slide to shift said barrel slightly upwardly and forwardly to a predetermined tiring position thereof, said connecting structure having two parallel opposite side surfaces, said body having parallel wall surfaces spaced precisely in correspondence with the spacing of said side surfaces of the connecting structure and simultaneously engaged by both of said side surfaces to accurately confine and locate said connecting structure and said barrel.

19. A gun as recited in claim 18, in which said connecting structure includes shims secured to opposite sides of the connecting structure and forming said side surfaces thereof.

20. A gun including a body, a barrel movably mounted to said body, a bushing disposed about and positioning said barrel toward the muzzle end thereof, a slide mounted to the body for front to rear recoiling movement relative thereto, a connecting structure projecting downwardly from the breech end of said barrel, a link, a first pin attaching said link to said body for relative pivotal movement about a rst transverse axis, a second pin attaching said link to said connecting structure for relative pivotal movement about a second transverse axis above said first axis and in a relation mounting the breech end of said barrel for slight rearward and downward movement, said slide having a portion engageable with said barrel upon forward movement of the slide to shift said barrel slightly upwardly and forward to a predetermined firing position thereof, a locking arm at the outside of the body engageable with said slide to retain it in a rearwardly displaced position upon firing of a last round from the gun, said arm being formed separately from said first pin and containing an opening, said rst pin being received within said opening and having a head at one end thereof at the outer side of said arm movably retaining it to the body, and means at the second end of said first pin removably connectable thereto to releasably lock said first pin against removal from the body.

21. A gun including a body, a barrel movably mounted to said body, a bushing disposed about and positioning said barrel toward the muzzle end thereof, a slide mounted to said body for front to rear recoiling movement relative thereto, means at the underside of the breech end of said barrel mounting the barrel for slight upward and downward swinging movement, said barrel having at the top of its breech end an arcuate rearwardly projecting lug, said slide containing a recess receiving said lug and having two opposite side wall surfaces engaged simultaneously by opposite sides of said lug to precisely locate the lug against lateral shifting movement.

22. A gun including a body, a barrel movably mounted to said body, a bushing disposed about and positioning said barrel toward the muzzle end thereof, a slide mounted to said body for front to rear recoiling movement relative thereto, means at the underside of the breech end of said barrel mounting the barrel for slight upward and downward swinging movement, said barrel having at the top of its breech end an arcuate rearwardly projecting lug, said slide containing a recess receiving said lug and having two opposite side wall surfaces and an end surface engaged simultaneously by opposite sides of said lug and an end thereof respectively to precisely locate the lug against lateral and longitudinal shifting movement.

23. A gun including a body, a barrel movably mounted to said body, a bushing disposed about and positioning said barrel toward the muzzle end thereof, a slide mounted to the body for front to rear recoiling movement relative thereto, a connecting structure projecting downwardly from the breech end of said barrel and bifurcated to form two parallel depending arms, a link having a projection extending upwardly between said two arms, a rst pin attaching said link to said body for relative pivotal movement about a rst transverse axis, a second pin attaching said two arms of said connecting structure to said link for relative pivotal movement about a second transverse axis above said first axis and in a relation mounting the breech end of the said barrel for slight rearward and downward movement, said slide having a portion engageable with said barrel upon forward movement of the slide to shift said barrel slightly upwardly and forwardly to a predetermined tiring position thereof, said link having two upper surfaces movable into engagement upwardly against two undersurfaces respectively of said connecting structure, at the lower ends of said arms respectively, in abutting engagement with said undersurfaces upon movement of said barrel to said firing position.

24. A gun including a body, a barrel movably mounted to said body, a bushing disposed about and positioning said barrel toward the muzzle end thereof, a slide mounted to the body for front to rear recoiling movement relative thereto, a connecting structure projecting downwardly from the breech end of said barrel and bifurcated to form two parallel depending arms, a link having a projection extending upwardly between and confined between said two arms, a rst pin attaching said link to said body for relative pivotal movement about a lirst transverse axis, a second pin attaching said two arms of said connecting structure to said link for relative pivotal movement about a second transverse axis above said first axis and in a relation mounting the breech end of said barrel for slight rearward and downward movement, said slide havin-g a portion engageable with said barrel upon forward movement of the slide to shift said barrel slightly upwardly and forwardly to a predetermined firing position thereof, said link having three upper surfaces movable into engagement upwardly against three undersurfaces of the connecting structure in abutting engagement therewith upon movement of said barrel to said tiring position, said three upper surfaces and three undersurfaces being located at the lower ends of said arms and at the upper end of said projection.

25. A gun including a body, a barrel movably mounted to said body, a bushing disposed about and positioning said barrel toward the muzzle end thereof, and means mounting said barrel for slight upward and downward swinging movement of the breech end thereof relative to said bushing and about essentially an axis extending transversely of said bushing at essentially the location thereof, said bushing having a rst bushing surface positioned to engage and embrace the underside of said barrel at a location forwardly of said axis, and having a second bushing surface positioned to engage and embrace the upper side of said barrel at a location rearwardly of said axis, said surfaces being positioned for movement of said barrel into and out of locating engagement therewith by said slight upward and downward swinging movement respectively of the breech end of the barrel, said bushing having two additional bushing surfaces positioned to essentially engage and locate the underside and upper side respectively of the barrel when it is swung downwardly, said additional surfaces being located rearwardly and forwardly respectively of said transverse axis and merging with said rst and second surfaces at substantially a common transverse plane containing said axis.

26. A bushing to be mounted in a gun slide to slidably receive and locate a coacting gun barrel which is mounted for slight downward and upward swinging movement about a predetermined transverse axis relative to the bushing, said bushing having a rst bushing surface positioned to engage and embrace the under side of said barrel at a location forwardly of said axis, and having a second bushing surface positioned to engage and embrace the upper side of said barrel at a location rearwardly of said axis, said surfaces being positioned for movement of said barrel into and out of locating engagement therewith by said slight upward and downward swinging movement respectively of the breech end of the barrel, said bushing having two additional bushing surfaces positioned to essentially engage and locate the underside and upper side respectively of the barrel when it is swung downwardly through a small angle less than two degrees.

References Cited bythe Examiner UNITED STATES PATENTS 984,519 2/ 1l Browning 42--7 2,090,657 8/ 37 Williams 89-196 2,625 ,7 66 1/ 5 3 Simpson 42--75 2,776,602 l/ 57 Sturtevant 89-196 2,910,918 11/59 Jewett 89-196 3,110,223 1 1/ 63 Schlappich 89-196 BENJAMIN A. BORCHELT, Primary Examiner.

FRED C. MATTERN, JR., Examiner. 

1. A GUN INCLUDING A BODY, A BARREL MOVABLY MOUNTED TO SAID BODY, A BUSHING DISPOSED ABOUT AND POSITIONING SAID BARREL TOWARD THE MUZZLE END THEREOF, AND MEANS MOUNTING SAID BARREL FOR SLIGHT UPWARD AND DOWNWARD SWINGING MOVEMENT OF THE BREECH END THEREOF RELATIVE TO SAID BUSHING AND ABOUT ESSENTIALLY AN AXIS EXTENDING TRANSVERSELY OF SAID BUSHING AT ESENTIALLY THE LOCATION THEREOF. SAID BUSHING HAVING A FIRST BUSHING SURFACE POSITIONED TO ENGAGE AND EMBRACE THE UNDERSIDE, OF SAID BARREL AT A LOCATION FORWARDLY OF SAID AXIS, AND HAVING A SECOND BUSHING SURFACE POSITIONED TO ENGAGE AND EMBRACE THE UPPER SIDE OF SAID BARREL AT A LOCATION REARWARDLY OF SAID AXIS, SAID SURFACES BEING POSITIONED FOR MOVEMENT OF SAID BARREL INTO LOCATING ENGAGEMENT WITH BOTH OF SAID SURFACES BY SIDE SLIGHT UPWARD SWINGING MOVEMENT OF THE BREECH END OF THE BARREL, AND FOR MOVEMENT OF THE BARREL OUT OF SAID LOCATING ENGAGEMENT WITH BOTH OF SAID SURFACES BY SAID SLIGHT DOWNWARD SWINGING MOVEMENT OF THE BREECH END OF THE BARREL, SAID FIRST BUSHING SURFACE EXTENDING REARWARDLY SUBSTANTIALLY TO A TRANSVERSE PLANE CONTAINING SAID AXIS AND SAID SECOND BUSHING SURFACE EXTENDING FORWARDLY SUBSTANTIALLY TO THE SAME TRANSVERSE PLANE TO CONFINE THE BARREL BETWEEN TEH EXREMITIES OF SAID SURFACES DURING SAID PIVOTAL MOVEMENT. 